An espresso coffee maker or a drip coffee maker includes a top cover, a coffee maker body and a brewing chamber assembly. The brewing chamber assembly comprises: a brewing chamber cover fixed at the bottom of the top cover, a brewing chamber body fixed in the coffee maker body, a brewing chamber seat installed in the coffee maker body around the brewing chamber body, and a sealing ring installed between the brewing chamber cover and brewing chamber seat. Normally, the sealed brewing chamber is formed manually by the following steps: the first step is to close the top cover, and the second step is to rotate the brewing chamber seat about the vertical central axis of the brewing chamber body manually with the handle of the brewing chamber seat, so as to make the brewing chamber seat and the brewing chamber cover rotate relative to each other and become sealed. With the prior method, closing the top cover and forming the sealed brewing chamber had to be implemented in separate steps, the brewing chamber cover had to be aligned with the brewing chamber seat when rotating, and a relatively large force had to be applied due to the sealing ring provided in the brewing chamber seat. Accordingly, users found them inconvenient to operate.
An object of the present invention is to overcome the shortcomings of the prior art by providing a locking device for a coffee brewing apparatus of an automatic coffee maker, which automatically locks the coffee brewing chamber as the top cover is closed on the coffee maker body.